Russian Journal of General Chemistry, Vol. 72, No. 1, 2002, pp. 44 45. Translated from Zhurnal Obshchei Khimii, Vol. 72, No. 1, 2002,
pp. 49 50.
Original Russian Text Copyright
2002 by Sharutin, Sharutina, Egorova, Ivanenko, Bel’skii.
Synthesis and Structure of Triphenylbismuth Difluoride
V. V. Sharutin, O. K. Sharutina, I. V. Egorova, T. K. Ivanenko, and V. K. Bel’skii
Blagoveshchensk State Pedagogical University, Blagoveshchensk, Russia
Received July 18, 2000
Abstract The reaction of triphenylbismuth dichloride with sodium fluoride in acetone leads to formation
of triphenylbismuth difluoride in 73% yield. The X-ray diffraction data show that the bismuth atom in the two
symmetrically independent molecules of bismuth difluoride has a trigonal-bipyramidal coordination with
equatorial fluorine atoms. The Bi F and Bi C distances are 2.53(1) 2.59(1) and 2.10(3) 2.22(2) , respec-
tively, and the FBiF angle is 175.1(5) .
It is known that the triphenylbismuth difluoride
prepared from triphenylbismuth dibromide and potas-
sium fluoride melts at 127.5 C. At the same time, the
reaction of triphenylbismuth dihalide with silver
fluoride in benzene evidently leads to another crystal
modification which melts at 158.5 159 C [2]. We
slightly changed the conditions of synthesis of tri-
phenylbismuth difluoride I melting at 127.5 C (reac-
tion of sodium fluoride and triphenylbismuth di-
chloride in aqueous acetone) and studied its crystal
structure.
EXPERIMENTAL
X-ray diffraction analysis of crystals of tri-
phenylbismuth difluoride (I). The unit cell para-
meters and the intensities of 1116 unique reflections
with I > 2 (I) were measured on an Enraf Nonius
CAD-4 automatic diffractometer ( MoK radiation,
0.71073 , Nb filter, 2 / scanning). The crystals
are orthorhombic; at 20 C, a 9.140(2)
, b
17.122(3) , c 22.339(4); V 3496(1) 3; space group
P212121, Z 8, dcalc 1.817 g/cm3. The structure was
solved by the heavy atom method and refined aniso-
tropically for non-hydrogen atoms and isotropically
for hydrogen atoms to R 0.0386 and RW 0.1104. All
the calculations were carried out using the SHELXL-
97 program package [4].
The X-ray diffraction data show that the bismuth
atom in the two symmetrically independent molecules
of compound I has a distorted trigonal-bipyramidal
coordination with axial fluorine atoms. The angles
between equatorial phenyl substituents are slightly
different [113.6(10) , 118.5(12) , and 127.9(12) in
molecule A and 118.2(11) , 120.5(9) , and 121.3(11)
in molecule B], but axial FBiF angles are practically
equal to each other [175.1(5) and 175.6(5) ]. Note
that in the molecule of triphenylbismuth bis(trifluoro-
acetate) in which the bismuth atom has the coordina-
tion number 7 the respective angles are 110.1(3) ,
109.2(3) , and 140.6(3) [3].
Triphenylbismuth difluoride (I). To a soilution
C11
C12
C10
C9
F2
C5
C3
C8
C6
C2
C7
C1
Bi1
C4
The bismuth atom in molecule A lies practically
in the equatorial plane (the deviation from the plane
is 0.001 ), while in molecule B this deviation is
larger (0.017 ). Both in A and in B, different torsion
angles of phenyl rings with respect to the equatorial
plane are observed: 72.9 , 67.2 , and 31.6 in A and
115.7 , 35.7 , and 103.5 in B. The spatial arrange-
ment of molecule A of compound I is presented in the
figure. The atomic coordinates are listed in Table 1,
and the bond lengths and bond angles, in Table 2.
C18
C13
F1
C17
C16
C14
C15
Overall view of molecule A of compound I.
1070-3632/02/7201-0044$27.00 2002 MAIK Nauka/Interperiodica
Sharutin
